1. Field of the Invention
The invention relates generally to computer architectures and, more particularly, to a method and an apparatus for performing error checking enablement in a computer.
2. Description of Related Art
Upon initialization, electronic components, such as processors, generally perform self-tests on power-up, which is commonly referred to as power-on-reset (POR). The POR typically involves setting latches within the processor to known states, such as logical zeros. After coming out of POR, error-checking logic verifies that the condition of certain signals, i.e., latches, is as expected. The error-checking logic reports an error condition if the circuits do not match the expected values.
Many latches, however, are connected in a serial fashion within a pipeline, and may require two or more clock cycles before reaching a known valid state (in other words, invalid states may exist in the latches directly after coming out of POR). In order to verify the operation of these circuits, therefore, additional logic and/or circuitry is required to prevent an error condition from being reported prior to the complete initialization of the circuit. Furthermore, the additional logic and/or circuitry usually creates additional problems, such as debugging problems, and/or requires additional resources, such as a validity bit.
Therefore, there is a need for a method and a system to selectively enable post-POR error checking in order to suppress false errors.
The present invention provides a method and an apparatus for suppressing false errors of one or more circuits by selectively enabling error checkers. The method and apparatus utilizes a shifter to shift an enable bit at the rate at which the one or more circuits become initialized. Errors are suppressed if the value from the shifter corresponding to the clock cycle the one or more circuits are initialized is not enabled.